3 sourced reports, with what to check before you buy. Each one links to the page it was reported on.
Worth checking
AMD T14 freezes when idle; blank screen + random restart, fixed by BIOS update
On the Qubes OS forum, owners of AMD T14/P14s machines report freezes when idle and a blank screen followed by a random restart; one user reports a new BIOS update resolved it, while another says a later firmware update reintroduced the problem.
What to check. AMD T14 owners report idle freezes and blank-screen restarts that are firmware-related: updating the BIOS can fix them, but a later firmware update can bring the problem back. Keep the BIOS current and check the Lenovo community for the latest firmware before assuming hardware failure.
T14 Gen1 Ryzen freezes with pixel artifacts; suspected iGPU overheating
An owner reports a T14 Gen1 Ryzen that intermittently freezes and fails to boot after shutdown; a forum expert replies 'würde mal "überhitzung" vermuten so langsam verabschiedet sich das Teil b.z.w. die igpu' and notes repair costs over 200 EUR.
What to check. On a Gen1 AMD T14, an intermittent freeze with pixel artifacts that worsens when the lid is moved points to the integrated GPU/thermal issue rather than software; it is hard to self-diagnose and costly to repair (over 200 EUR), so check warranty status before paying for a repair.
T14 Gen5 AMD sleep/wake failure persists across generations
A reviewer of the T14 G5 reports the AMD variants of the T14 line repeatedly fail to wake from sleep, and that Lenovo has not issued a fix for 3+ years.
What to check. If you are choosing an AMD T14 Gen5, expect a known sleep/wake defect that Lenovo has not fixed across multiple generations; buyers report it is not a unit defect (3 replacements all showed it), so it is a platform-level firmware issue to plan around.
These reports come from the pages linked under each item: owner forums, repair guides and workshops. They are not a diagnosis of any one unit, and a careful check of the one you are buying still applies.
Text from the Kriko Laptops catalog, version 0.1.1, under the CC-BY-SA-4.0 license.